Probably the most famous poem ever written by Walt Whitman, this is a memorial to the then-recently assassinated President Abraham Lincoln.
When lilacs last in the door-yard bloom'd,
And the great star early droop'd in the western sky in the night, 
I mourn'd--and yet shall mourn with ever-returning spring. 

O ever-returning spring! trinity sure to me you bring;
Lilac blooming perennial, and drooping star in the west,
And thought of him I love. O powerful, western, fallen star!
O shades of night! O moody, tearful night!
O great star disappear'd! O the black murk that hides the star!
O cruel hands that hold me powerless! O helpless soul of me!
O harsh surrounding cloud, that will not free my soul!

In the door-yard fronting an old farm-house, near the white-wash'd palings,
Stands the lilac bush, tall-growing, with heart-shaped leaves of rich green,
With many a pointed blossom, rising, delicate, with the perfume strong I love,
With every leaf a miracle......and from this bush in the door-yard,
With delicate-color'd blossoms, and heart-shaped leaves of rich green,

A sprig, with its flower, I break. In the swamp, in secluded recesses,
A shy and hidden bird is warbling a song.

Solitary, the thrush,
The hermit, withdrawn to himself, avoiding the settlements,
Sings by himself a song.

Song of the bleeding throat!
Death's outlet song of life--(for well, dear brother, I know
If thou wast not gifted to sing, thou would'st surely die.)

Over the breast of the spring, the land, amid cities,
Amid lanes, and through old woods, (where lately the violets peep'd from the ground,spotting the gray debris;)
Amid the grass in the fields each side of the lanes -- passing the endless grass;
Passing the yellow-spear'd wheat, every grain from its shroud in the dark-brown fields uprising;
Passing the apple-tree blows of white and pink in the orchards;
Carrying a corpse to where it shall rest in the grave,
Night and day journeys a coffin.

Coffin that passes through lanes and streets,
Through day and night, with the great cloud darkening the land,
With the pomp of the inloop'd flags, with the cities draped in black,
With the show of the States themselves, as of crape-veil'd women, standing,
With processions long and winding, and the flambeaus of the night,
With the countless torches lit--with the silent sea of faces, and the unbared heads,
With the waiting depot, the arriving coffin, and the sombre faces,
With dirges through the night, with the thousand voices rising strong and solemn;
With all the mournful voices of the dirges, pour'd around the coffin,
The dim-lit churches and the shuddering organs--Where amid these you journey
With the tolling, tolling bells' perpetual clang;
Here! coffin that slowly passes, I give you my sprig of lilac.

(Nor for you, for one, alone;
Blossoms and branches green to coffins all I bring:
For fresh as the morning--thus would I carol a song for you, O sane and sacred death.
All over bouquets of roses,
O death! I cover you over with roses and early lilies;
But mostly and now the lilac that blooms the first,
Copious, I break, I break the sprigs from the bushes;
With loaded arms I come, pouring for you,
For you, and the coffins all of you, O death.)

O western orb, sailing the heaven!
Now I know what you must have meant, as a month since we walk'd
As we walk'd up and down in the dark blue so mystic,
As we walk'd in silence the transparent shadowy night,
As I saw you had something to tell, as you bent to me night after night,
As you droop'd from the sky low down, as if to my side, (while the other stars all look'd on;)

As we wander'd together the solemn night, (for something, I know not what, kept me from sleep;)
As the night advanced, and I saw on the rim of the west, ere you went, how full you were of woe;
As I stood on the rising ground in the breeze, in the cold transparent night,
As I watch'd where you pass'd and was lost in the netherward black of the night,
As my soul, in its trouble, dissatisfied, sank, as where you, sad orb,
Concluded, dropt in the night, and was gone.

Sing on, there in the swamp!
O singer bashful and tender! I hear your notes -- I hear your call;
I hear -- I come presently -- I understand you;
But a moment I linger -- for the lustrous star has detain'd me;
The star, my departing comrade, holds and detains me.

O how shall I warble myself for the dead one there I loved?
And how shall I deck my song for the large sweet soul that has gone?
And what shall my perfume be, for the grave of him I love?

Sea-winds, blown from east and west,
Blown from the eastern sea, and blown from the western sea, till there on the prairies meeting:
These, and with these, and the breath of my chant, I perfume the grave of him I love.

O what shall I hang on the chamber walls?
And what shall the pictures be that I hang on the walls,
To adorn the burial-house of him I love?

Pictures of growing spring, and farms, and homes,
With the Fourth-month eve at sundown, and the gray smoke lucid and bright,
With floods of the yellow gold of the gorgeous, indolent, sinking sun, burning, expanding the air;
With the fresh sweet herbage under foot, and the pale green leaves of the trees prolific;
In the distance the flowing glaze, the breast of the river, with a wind-dapple here and there;
With ranging hills on the banks, with many a line against the sky, and shadows;
And the city at hand, with dwellings so dense, and stacks of chimneys,
And all the scenes of life, and the workshops, and the workmen homeward returning.